Solar wind discontinuities spatial evolution and energetic ion scattering


Zijin Zhang1 Anton Artemyev1 Vassilis Angelopoulos1 Shi Chen1

1 Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles

Introduction & Motivation

‘Discontinuities’ are discontinuous spatial changes in plasma parameters/characteristics and magnetic fields (Colburn and Sonett 1966).

Current sheets in the heliosheath: Voyager 1, 2009 Characteristics of magnetic field

Söding et al. (2001) studied the radial distribution of discontinuities in the solar wind.

Discontinuities between 0.3 and 19 AU

Joint observations of JUNO & ARTEMIS & Other missions really provides a unique opportunity!!!

Method

  • We use (Liu et al. 2022) method to identify IDs, which has better compatibility for the IDs with minor field changes.
  • Then the minimum variance analysis is applied to each ID event to obtain the boundary normal (LMN) coordinate and extract IDs’ features.
  • Hamiltonian model is applied for investigation of ion dynamics in the solar wind discontinuity configuration.

Results

Colburn, D. S., and C. P. Sonett. 1966. “Discontinuities in the Solar Wind.” Space Science Reviews 5 (4): 439–506. https://doi.org/10.1007/BF00240575.
Liu, Y. Y., H. S. Fu, J. B. Cao, Z. Wang, R. J. He, Z. Z. Guo, Y. Xu, and Y. Yu. 2022. “Magnetic Discontinuities in the Solar Wind and Magnetosheath: Magnetospheric Multiscale Mission (MMS) Observations.” Astrophysical Journal 930 (1): 63. https://doi.org/10.3847/1538-4357/ac62d2.
Söding, A., F. M. Neubauer, B. T. Tsurutani, N. F. Ness, and R. P. Lepping. 2001. “Radial and Latitudinal Dependencies of Discontinuities in the Solar Wind Between 0.3 and 19 AU and -80° and +10°.” Annales Geophysicae 19 (7): 667–80. https://doi.org/10.5194/angeo-19-667-2001.

Solar wind discontinuities evolve in space with occurrence rate decreasing, thickness increasing and current density decreasing with distance from the Sun. And they are probably generated locally beyond 1 AU.

Background sheared magnetic field plays an important role in determining the efficiency of ion pitch angle scattering, and characterize three ion populations: transient, trapped, regular.